Scientists develop fast, accurate test to detect bio-terror agent

Washington, April 13 (IANS) Scientists have developed a simple, accurate and highly sensitive test to detect and quantify ricin, a highly lethal toxin with potential use as a bioterrorism agent. Ricin, a protein extracted from castor beans, can be in the form of a powder, mist, pellet or solution. When injected or inhaled, as little as one-half mg of ricin is lethal to humans.

No antidote is available. The most notorious ricin attack took place in London in 1978, when Bulgarian dissident Georgi Markov died after being stabbed with an umbrella that injected a ricin-coated pellet into his leg.

The ricin assay was developed in the lab of Vern Schramm, biochemistry professor at Albert Einstein College of Medicine and study co-author. The assay detects small amounts of ricin more accurately and faster than ever before.

Users of the assay would place samples of potentially adulterated food, or swabs used to wipe potentially contaminated surfaces, into a few drops of a mixture of reagents; the mixture will emit light if ricin is present, with higher luminescence indicating greater concentrations of the toxin.

Schramm believes the assay’s most immediate application is for discovering drugs that could serve as antidotes for ricin poisoning.

“Previously we had to rely on laborious, multi-step methods to see if a compound was preventing ricin from working, which is probably why no antidote to ricin has yet been discovered,” explained Schramm.

After ricin enters cells, it kills them by interfering with their ability to make proteins; a basic cellular function, said an Einstein release.

Ricin has also been used as an anticancer agent by linking it to antibodies that are home to tumours and deliver the ricin ‘warhead’ to kill cancer cells. Einstein scientists indicate that detection of ricin in cancer trials may be an early use of this technology.